| Change of the Platelet Golgi Apparatus After Ischemic StrokeBackground:Stroke, a brain attack, is the leading cause of disability and the third leading cause of death. Ischemic stroke is by far the most frequent type of stroke. Until now, platelet activation is thought to be a very important cause of the ischemic stroke. Studies showed that the conglutination and congregation of platelets increased significantly in the whole process of the infarction, the activated platelets synthesized and secreted multiple inflammatory factors. Transient ischemic induced platelet activation and platelet accumulation in the brain microvessels. Blood Platelet structure changed in the patients with stroke acute cerebrovascular infarction.Golgi complex is an important organ of platelet, for its key role in synthesizing, secretion, and transportation. In our early research, we have found that the structure of neuron golgi complex changed during brain ischemia.CD40L was transferred onto the membrane after platelet was activated, and then CD40L clipped into sCD40L. After acute ischemia, plasma sCD40L increased significantly. Platelet activation existed in the patients of diabetes, hypertension and Homocysteine(Hcy)with increased sCD40L expression. Almost 95% of sCD40L were from platelets in blood. Until now, the exact way of the CD40L transportation and secretion is not clear.Purpose:The aim of this study was to evaluate the structural change of the platelet Golgi apparatus after stroke, and to investigate the potential role of the Golgi apparatus in the expression of platelet CD40LMethods:Platelets of 20 patients were observed by electron microscopy and Immuno-electron microscopy with the platelets of 20 healthy volunteers as control. Suspensions of platelets got from 20 healthy volunteers were used to evaluated the role of the Golgi apparatus in the expression of CD40L on platelets by flow cytometry. The expression of CD40L on the activated platelets was observed after the Golgi apparatus was interdicted by the Brefeldin A(BFA) compared with normal platelets and the platelets activated by ADP.Results:The Golgi apparatus changed obviously after stroke, the main change was the increasing and widening of the Golgi vesicles and stacks, and there were some a granules around them.αgranules in platelet decreased significantly after stroke(P<0.05). The change remained obviously until the 15th day after stroke. The expression of CD40L on the activated platelets increased significantly compared with normal platelets(P<0.05). Compared with the platelets activated by ADP, the CD40L expression decreased on the platelets which the Golgi apparatus were interdicted by Brefeldin A before activated by ADP(P<0.05).Conclusions:The Golgi apparatus may play an important role in the pathophysiology of stroke. The Golgi apparatus may be a potential target for inhibition of CD40L synthesis and transfer in platelet. The Effect of sCD40L on the Brain ischemic injuryBackground:After acute ischemic stroke, plasma sCD40L increased significantly. Platelet activation exist in patients of diabetes, hypertension, Homocysteine, and sCD40L increased in these patients.95 percent of sCD40L were from platelets in blood. sCD40L is now thought to be a marker to evaluate the severity of stroke. sCD40L increasing is related with the brain vascular disease.SCD40L is soluble form of the CD40L. sCD40L can bind to three receptors(CD40,α5β1 and aⅡbβ3). All of the three receptors expressed on the platelet. CD40 expressed on B cells, activated T cells, DC, endothelium, monocyte, platelet and also expressed on many kinds of cells in CNS.Breakage of BBB, leucocyte infiltration and microglia activation are main pathology changes after the onset of stroke. CD40 on the Activated microglia increased. sCD40L can activate microglia. There is no report on the relation of the sCD40L and brain ischemic injury so far.Purpose:Study the role of sCD40L in the brain ischemic injury. Investigate the potential mechanisms of sCD40L on the brain ischemic injury.Methods:132 SD rats were divided into 6 groups randomly which are control group. 1st day group,3th day group,5th day group, low dose rsCD40L group and high dose rsCD40L group. The control group were executed after one day. the rest groups were executed on the 1st.3th,5th day respectively. The methods of HE stain, immunochemistry, immunofluorescence, and western blot were put in use to observe the expression of the CD40, ClqA, NF-K Bp65 in the brain tissue after ischemia. The brain water content and the EB content in the brain tissue were also observed.Results:1 HEThe brain tissues are actually normal in the control group. The neuron death and microglia activation can be observed in the brain ischemic groups. These changes also exist in the 5th day group. The neuron death and microglia activation increased in the rsCD40L groups.2 Brain water content and EB contentThe brain water content and the EB content in the brain tissue increased significantly in the brain ischemic groups compared to the control group(p<0.05). Compared to the brain ischemic groups, a significant increase can also be observed in rsCD40L groups (p<0.05).3 Immunochemistry and immunofluorescenceCD40 expressed on the membrane, ClqA expressed in the cytoplasm and the NF-kBp65 were observed both in the cytoplasm and nuclear. The expression of the three increased after brain ischemia.4 Western blotCD40, ClqA and NF-kBp65 expressed less in brain tissue, while increased at the 1,3,5 day(p<0.05)after brain ischemia. CD40 and NF-xBp65 increased significantly after brain ischemia(p<0.05). ClqA expression significantly increased at 3th day compare to other groups. All the three increased significantly in the high dose rsCD40L group compared to the low dose group (p<0.05).Conclusions: 1 sCD40L strengthen the brain ischemic injury.2 sCD40L may strengthen the brain ischemic injury via the activation of the complement and increasing of the inflammation in the ischemic brain tissue.
|
PDF Full Text Request